And that trip to the moon cost $150 billion (in 2010 dollars). OF COURSE it brought about new discoveries, inventions, tools, etc-- IT WAS $150 BILLION! Saying that we discovered new things in the process of spending that much money does not mean we should automatically do it again.

If our true motivation for a trip to the moon is to develop new things, then we have to ask: does spending that money on a trip to the moon result in more inventions than spending it on the National Institutes of Health? or the National Science Foundation? or the Department of Energy?

We NEED to spread out, so that a single epidemic, or a catastrophic event doesn't wipe us out!

There's no realistic way of spreading beyond Mars. And Mars itself isn't really a better place to survive a catastrophic event. It would make more sense to build a couple of deep underground (or underwater) bunkers on earth, where a few people can take shelter from this catastrophic event. It would be several orders of magnitude cheaper, and more effective. At least, when the event has passed, you can climb out, and breathe the air, drink the water, and grow food.

He's right in that jobs don't create wealth. Work creates wealth. For the generated wealth it doesn't matter if that work is done by a self-employed worker, by an employee, by a slave or by a robot. What differs is how the resulting wealth is distributed.

If jobs created wealth, the east block states would have been incredibly wealthy because there everyone had a job.

If we can refine fuel and materials from lunar ores (possible, in theory) then the moon would make a great staging point to fuel up or perform final assembly for long missions. Instead of trying to lift obscene quantities of fuel and finished materials out of a much bigger gravity well, you just boost up the hard to build stuff with as little fuel as possible, and then slap it all together with moon-tape and ExxonMoonble.

All other things equal, yes. Unfortunately heavy mining equipment usually depends on big diesel engines that need diesel and water as coolant, neither of which are easily available on the moon. So for power we'd need great fields of solar panels or something similar and without coolant dry mining would require far more frequent changes of drill heads. Then you have the same issue with smelters, they require huge amounts of energy so add more solar arrays. Then you need huge hydraulic presses to make it into sheet metal, again another power hog so add even more solar arrays. And we still only have sheet metal.

Ore mining is heavy industry, like really heavy industry. Here on earth it seems so basic, only costing a few dollars but on the moon it would actually be a very, very complicated and expensive project. It would be a great achievement if we even manged to create fuel for an empty return rocket, mining ore is extremely much harder. And even if we could do that, it wouldn't make sense to send a rocket down to the moon to bring fuel back up, only make it a bit cheaper to do a moon mission. Going directly to Mars really has few disadvantages that I can see.